Create a Wordpress page template in order to retrieve subpages group by letter.

We need to create one WordPress page template capable of returning the child pages of the current [login to view URL] should be sorted alphabetically and separated by their respective first letters (A - B - C etc.). A navigation bar provides quick access to these letters . An image can be returned. Those images are Featured Images of Child pages. We provide the original source code of this page (in attachement). CSS and HTML classes are already present. Simply edit PHP of this page to query on Wordpress pages as explained above. We provide the original source code. So, you don't have to create Sidebar/header etc. Just edit PHP of this Wordpress template page. Eg of page running : [login to view URL]